Pick energy efficient appliances. The third largest energy use in dwelling units is for appliances. Refrigerators consume the most energy because they run 24 hours/day, every day of the year, maintaining a 30 degree temperature difference (65° – 35°) between the air in the kitchen and the air inside the refrigerator, and perhaps twice that between the air in the kitchen and that in the freezer (65° – 0°). The best refrigerators can be 25-30% more energy efficient than the worst in any particular size category.